golang.org/x/sys v0.23.0: unix.Pipe

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify golang.org/x/sys/unix.Pipe in pkg:golang/golang.org/x/sys@v0.23.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.23.0
Demonstrate these symbols/APIs:
  - golang.org/x/sys/unix.Pipe

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:508eeef745bddfbf0af4bae241a2e552826791d643e3ab8feb82a38bd69d5ce7","contract":["unix.Pipe returns EINVAL when passed a slice with fewer than 2 elements","unix.Pipe creates a unidirectional pipe and populates p[0] (read end) and p[1] (write end) with valid file descriptors","data written to p[1] via unix.Write is read back intact from p[0] via unix.Read"],"goal":"verify golang.org/x/sys/unix.Pipe in pkg:golang/golang.org/x/sys@v0.23.0","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.23.0"],"schemaVersion":1,"symbols":["golang.org/x/sys/unix.Pipe"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/sys@v0.23.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.23.0","symbols":["golang.org/x/sys/unix.Pipe"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.22.0

require golang.org/x/sys v0.23.0

golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

package main

import (
	"fmt"
	"os"

	"golang.org/x/sys/unix"
)

func CreatePipe() ([2]int, error) {
	var fds [2]int
	if err := unix.Pipe(fds[:]); err != nil {
		return fds, fmt.Errorf("pipe failed: %w", err)
	}
	return fds, nil
}

func main() {
	fds, err := CreatePipe()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error creating pipe: %v\n", err)
		os.Exit(1)
	}
	defer unix.Close(fds[0])
	defer unix.Close(fds[1])
	fmt.Printf("Pipe created with FDs: [%d, %d]\n", fds[0], fds[1])
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/sys/unix.Pipe in pkg:golang/golang.org/x/sys@v0.23.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.23.0"
  ],
  "symbols": [
    "golang.org/x/sys/unix.Pipe"
  ]
}

package main

import (
	"errors"
	"fmt"
	"os"

	"golang.org/x/sys/unix"
)

func main() {
	// Assertion 1: unix.Pipe returns EINVAL when passed a slice with fewer than 2 elements
	var short [1]int
	if err := unix.Pipe(short[:]); !errors.Is(err, unix.EINVAL) {
		fmt.Fprintf(os.Stderr, "FAIL: expected EINVAL for short slice, got %v\n", err)
		os.Exit(1)
	}

	// Assertion 2: unix.Pipe creates a unidirectional pipe returning valid read and write file descriptors
	var fds [2]int
	if err := unix.Pipe(fds[:]); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Pipe failed: %v\n", err)
		os.Exit(1)
	}
	defer unix.Close(fds[0])
	defer unix.Close(fds[1])

	if fds[0] < 0 || fds[1] < 0 || fds[0] == fds[1] {
		fmt.Fprintf(os.Stderr, "FAIL: invalid pipe descriptors: [%d, %d]\n", fds[0], fds[1])
		os.Exit(1)
	}

	// Assertion 3: data written to the write end (p[1]) is read intact from the read end (p[0])
	payload := []byte("csx-pipe-contract-test")
	wn, err := unix.Write(fds[1], payload)
	if err != nil || wn != len(payload) {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Write on pipe failed: wn=%d, err=%v\n", wn, err)
		os.Exit(1)
	}

	rbuf := make([]byte, len(payload))
	rn, err := unix.Read(fds[0], rbuf)
	if err != nil || rn != len(payload) {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Read on pipe failed: rn=%d, err=%v\n", rn, err)
		os.Exit(1)
	}

	if string(rbuf) != string(payload) {
		fmt.Fprintf(os.Stderr, "FAIL: pipe data mismatch: got %q, want %q\n", string(rbuf), string(payload))
		os.Exit(1)
	}
}